title: Uninsured adults presenting to US emergency departments: assumptions vs data.
abstract: BACKGROUND
  Emergency departments (EDs) are experiencing increased patient volumes and serve as a source of care of last resort for uninsured patients. Common assumptions about the effect of uninsured patients on the ED often drive policy solutions.
  
  
  OBJECTIVE
  To compare common unsupported statements about uninsured patients presenting to the ED with the best available evidence on the topic.
  
  
  METHODS
  OVID search of MEDLINE and MEDLINE in-process citations from 1950 through September 19, 2008, using the terms (Emergency Medical Services OR Emergency Service, Hospital OR emergency department.mp OR emergency medicine.mp OR Emergency Medicine) AND (uninsured.mp OR medically uninsured OR uncompensated care OR indigent.mp OR uncompensated care.mp OR medical indigency).
  
  
  METHODS
  Of 526 articles identified, 127 (24%) met inclusion/exclusion criteria. Articles were included if they focused on the medical and surgical care of adult (aged 18 to <65 years) uninsured patients in emergency settings. Excluded articles involved pediatric or geriatric populations, psychiatric and dental illnesses, and non-patient care issues.
  
  
  METHODS
  Statements about uninsured patients presenting for emergency care that appeared without citation or that were not based on data provided in the articles were identified using a qualitative descriptive approach based in grounded theory. Each assumption was then addressed separately in searches for supporting data in national data sets, administrative data, and peer-reviewed literature.
  
  
  RESULTS
  Among the 127 identified articles, 53 had at least 1 assumption about uninsured ED patients, with a mean of 3 assumptions per article. Common assumptions supported by the evidence include assumptions that increasing numbers of uninsured patients present to the ED and that uninsured patients lack access to primary care. Available data support the statement that care in the ED is more expensive than office-based care when appropriate, but this is true for all ED users, insured and uninsured. Available data do not support assumptions that uninsured patients are a primary cause of ED overcrowding, present with less acute conditions than insured patients, or seek ED care primarily for convenience.
  
  
  CONCLUSIONS
  Some common assumptions regarding uninsured patients and their use of the ED are not well supported by current data.
authors.affiliation: Robert Wood Johnson Clinical Scholars Program, University of Michigan School of Medicine, 1150 W Medical Center Dr, 6312 Medical Science Bldg 1, Ann Arbor, MI 48109-5604, USA. manyan@umich.edu
authors.forename: Manya F
authors.initials: MF
authors.lastname: Newton
authors.forename: Carla C
authors.initials: CC
authors.lastname: Keirns
authors.forename: Rebecca
authors.initials: R
authors.lastname: Cunningham
authors.forename: Rodney A
authors.initials: RA
authors.lastname: Hayward
authors.forename: Rachel
authors.initials: R
authors.lastname: Stanley
mesh_terms: D000328:Adult; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D006801:Humans; D008489:Medical Indigency / Q000706:statistics & numerical data; D017057:Medically Uninsured / Q000706:statistics & numerical data*; D008875:Middle Aged; D017664:Uncompensated Care / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology